Vacuum power control apparatus



Jan.l 24, 1939.` A, E, Roy v2,144,853

VACUUM POWER CONTROL APPARATUS Filed oct. 15, 1954 3 Sheets-Sheet l BY K W Lw.' n TTU/(NE yf Jan. 24, 1939. AE. RoY

VACUUM POWER QONTROL APPAATUS Filed Oct. l5, 1954 5 Sheets-Sheet 2 im y,

A TTORNEY.

Jan. 24,1939., A. E. ROY 2,144,853

VCUUM POWER CONTROL APPARATUS Filed oct. i5, 1934 3 ysheets-sheet s A4 TTG/MIE y,

arianna .lm-2c pn v2,144,245?. i

UNITED STAT-Es PATENT OFFICE s ,ulsss p v q 'vacuum rownn. connor. mmm

This invention relates to vacuumv power control apparatus, and morev particularly to apparatus which is operated manually in such a manner to utilize the suction created in the intake 5 manifold of an internal combustion engine for controlling the brakes of an automobile; truck,V

or trailer or other vehicle, whereby the manual effort of appLvingthe brakes is reduced to a minimum. f

.1o Another object of tnis'invfenuon is to provide al vacuum power control apparatus which is so arranged that the control valve structure thereof may be rigidly -mounted to the vehicle frame in'- l-'stead ofsuspended on or carried by a brake rod.

Another object is to provide a vacuum power control apparatus which reduces -to a minimum the manual effort required to effect operation of the brakes of trucks, trailers or other vehicles, y but which does not sacrince the sensitiveness obtained by manual control.

Another object is to provide, a vacuum power` control apparatus for vehicle brakes which is so connected with a mechanical brake mechanism that the brake' bands are caused to engage the brake drums and equalize before the apparatusn is brought into play whereby the additional braking .force supplied through the apparatus is applied uniformly to the severalbrakes.

An obiectyof this invention is to provide. a

novel valve for auch avacuum power control apto control both the application of sub-atmospheric and atmospheric air pressure to a preasm'e'responsive. device connected mechanically withhthe brakes of vehicles. AAnother object -of this invention is to provide a novel valve ofthe above character which with'` -but slightfchangin its construction may be used to perform diflerent functions in Vvariousparts of the control 40 Another object of this invention is `to'provide a novel valve which is positive in its action, while g the required lflexibility of operation for proper control of vehicle brakes and which is simplein construction andupkeep.

Another object of this invention is to provide'a novel regulating means for preventing.. overbrahng or excess application of sub-atmospheric pressure to the pressm'e responsive devices conf nected with the brakes. Another object of this invention is to provide a novel hand actuated 'operating means for a vacuum power control apparatus ofthe above c Another oblect this invention is toprovlde an apparatus of the above Whihs so arranged that should any elements thereof fail or should the vacuum lines break for. anyreason the brakes may still be mechanically operated by manual/control, thereby enabling the driver to maintain control even though the apparatus 5- is entirely Vout of commission.

Another object of this invention is to provide a control apparatus which is particularly sturdy and reliable of construction, easily installed, and

capable of withstanding the excessive use and l0 abuse without failure, thereby providing a control apparatus particularly suited for use on large trucks and their trailers. Certain modifications may be apparent to one versed in the art and 'such modications may l5 -well be made without departingfromthe spirit` of the invention as hereinafter described or hereinafter defined in the appended claims. 'lhe invention includes the .parts and combination of parts 'more particularly hereinafter 20K,

described and claimed.

Other objects, advantages and features of in vention may appear Vfrom the accompanying drawings, the subjoined idetail description and the appended claims. 25

The accompanying drawings illustrate the invention in some of the forms which Iv at present deem preferable.

Figure 1 is a substantially diagrammatical, par-- tially perspective view and side elevational view 30 of my apparatus in one of itsfonns showing the associated parts of the vehicle braking apparatus and a fragment ofthe intkemanifold of a ve-v hicle engine.

Fig. 2 is a longitudinal sectional view of the 35 kcontrol valve structure taken along a vertical plane with, the elements thereof shown in their normal positions. u

Fig. 3 is a transverse sectional view thereof l taken on line 343, Fig. 2. 1 40 Fig. 4 is a fragmentary substantially diagrammatical side elevational partly in perspective of a modified form ofdthe vacuum power control apparatus with .co-.acting portions of the vehicle shown fragmentarily, and the installation 45 being shown as particularly applied to a trailer braking Fig. 5 is an enlarged sectionalryiew of the hand controlled valve, taken on line Fig. 4, with the elements thereof shownj-ln their open or par- 5g tially open position and showing the adjustment device for regulating the vacuum vpower applied by the valve. A

Fig. 6 is a fragmentary elevational view of the upper portiono'f the haml-l control valve shown 55' stallation shown in Fig. 4.

Fig. 10 is an enlarged sectional view ofthe booster unit taken on line IIJ-I0, Fig. 9.

Referring to the drawings, particularly Figs. 1-3, it will be seen that the apparatus here embodied comprises generally a control valve structure to be described in more detail hereinafter, which is supported from a suitably positioned frame member 2 of a vehicle by a bar 3 either by a rigid connection 3 or a ball and socket joint means more particularly hereinafter referred to. A manifold line' 4 communicated between the valve structure I and an intake manifold 5 of a vehicle engine (not shown). The valve structure is also connected through a booster line 6 to a` booster unit 1, to be described in more detail hereinafter, and which is preferably suitably supported from another frame member 8 of the vehi cle. I

The control valve structure I and booster unit 1 are connected mechanically by rods 9 and I0 respectively with the brake rods II and brake pedal arm I2 of the vehicle braking system by a link and lever arrangement as follows: The rod 9 connected through a pivotal connection with the valve stemor rod 9 of th'e control valve structure I, and is pivotally connected to the upper or longer arm |3a of a link I3, which link in itsv normal position shown in Fig. 1 slopes downwardly and rearwardly. The link I3 which also acts as a lever is pivotally joined intermediate its ends to a connecting rod I4 which is in turn pivotally connected to the brake pedal arm I2. The lower or shorter arm I3b of the lever I3 is connected to the upper portion I5a of a. double ended rocker lever I5 which is secured at its mid-portion to a cross shaft I6 suitablyjournaled by means, not shown, from the vehicle frame. The other or lower portion |5b of the rocker lever I5 is joined to the aforementioned rod I0 that extends directly from the booster unit 1. The extreme portions of the cross shaft are provided with four lever arms I1 which are attached' to the usual rods I I that extend to and actuate the four brake rods II.

Reference is now directed to Figs. 2 and 3 which show in detail the construction of the control valve structure I. The mechanism ofthe valve structure I is enclosed in a main housing or body member 2| which is recessed at its forward side and covered by a dished cover 22 between which is interposed a gasket to make' an air tight connection. The recess in the housing comprises a major'diametered cylindrical portion 23 adjacent the cover, a concentric smaller diametered portion 24, forming therebetween an annular shoulder 25. An annular channel 26 is formed in theV shoulder radially outwardly of the smaller portion 24 of the recess and separated therefrom by a thin annular wall 21. The channel 26 connects f through a. passage 23 withthe pipe line 4 vfrom 'the manifold. The rear or closed side of the housing 2| is provided with a screwthreaded aperture which receives the threaded end of a hollow stem 29 which is attached to the supporting rod or bar 3. The booster line 6 is suitably attached to the stem 29.

The major diametered portion 23 of the housing 2| receives a cylindrical ring 30 which is provided with an outwardly anged end adapted to be retained between the cover 22 and the housing. The ring 30 and walls of the housing opposite the major portion 23 are pierced by a plurality of radiating atmospheric ports 3|. A screen 32is interposed between the ring 30 and lhousing wall and is secured to ring 30 in any suitable manner and serves to prevent foreign matter entering the housing.

A flexible partition 33, preferably formed of rubber or analogous material, is positioned with its periphery between the axially inner end of the ring 30 and the shoulder 25 and is not clamped, but instead, floats therebetween. The cover 22 is provided with a centrally disposed sleeve 34 that forms a bearing for, and in which slides a valve stem 9" that extends through the flexible plate 33 into the smaller recessed portion 24 and is here provided with a valve head 31. The valve head is substantially flat and thin. Its outer periphery is provided with a small bead or rim 3B which is di- 44rected toward the flexible plate, while adjacent the stem the valve head is provided with an annular boss 39 which bears against the central portion of the flexible plate 33. The boss 39 normally spaces the beaded rim 38 of the valve head 31 from the flexible floating plate 33.

Axially inwardly from the periphery. of the valve head 31, the flexible plate 33 is pierced by a plurality of exhaust apertures 40. A tension plate 4| of sheet material ts upon the stem 9" and is urged under tension against the side of the flexible plate 33 opposite from the valve head by a helical spring 42 which surrounds the stem and bears against the cover22., The tension plate 4| is provided with a channel 43 in its side and opening towards the flexible plate and opposite the apertures 40 therethroug pierced by exhaust holes 44 to insure communication between the smaller portion 24 and the atmosphere through the ports 3|.

' In brief, the interior of the control-valve stmoture is divided into a chamber A open to the at-- mosphere, a chamber B communicating with the booster line 6 and the channel 2B communicating with the manifold line 4.

The marginall portion of the flexible plate forms a flap valve portion 45 which bears against the shoulder and controls communication between the channel 26 and chamber B around the edge of wall 21, while the central portion of said flexible plate forms a flexible valve seat portion 46 for the valve head 31 to coact therewith Vand seal or control communication between Said channel is to Figs. 9 and 10 as well as Fig'. 1. The booster vunit comprises a pair of casingv members 5| which have a greater length than vertical width and such booster unit readily fits in or below the vehicle frame. -Each casing member comprises a flat side 52 with outwardly sloping walls therearound terminating in a flange 53.

One of the casing members 5| is provided with lugs 54 with whichv to permit attachment of the booster unit directly to the vehicle frame 8 as shown in Fig. 1 or to a bracket 54 as shown in Figs. 9 and '10. The casing members or the like,

guasta s' M I 3 are secured together witnbolts sspassing through said flanges 53 and clamp therebetween a diaphragm'55.

Said diaphragm is capable of considerable lateral movement into either casing and divides the enclosure formed thereby into two chambers C and D. Chamber is exposed to the atmospliere by reason of a centrally disposed opening 55 through which rod l0 freelysextends while chamber Dis connected with the booster line 6 byrany suitable connection as at 93. Therod I0, which in Fig. 1 is joined in the arm Ilb'of the rocker lever I5, extends through the opening 55 and diaphragm ,55, and is secured to said v,15 diaphragm by `a pair of nuts 51 which bear against washer plates 58 on-opposite sides kof the diaphragm. A spring 5! in chamber D bears against one flat side 52 and Yone of the washer plates 55 to urge the diaphragm in brake releasing position,v that is, in the direction to reduce the volume of chamber C and extend the rod I0, and such spring 59 also tends to reduce channg or vibration of thediaphragm 55. Operation ofthe vacuum power' control apparatus shown in Fig. 1 is as follows: f v

y When the parts are in the position shown in Fig. 1 the brakes are'in their normal or released position. The parts of the valve structure I are in the positions shown in Fig. 2; that is, the iiap valve portion .45` of the flexible plate. valve is seated over the channel 2l by reason of the subatmospheric pressure therein and the atmospheric pressure in chamber A. and the valve head 31 is clear of the ilexlble valve seat portion 35 46. The `diaphragm 55 of the booster unit is in the position relative `to Ythe casing members shown in Fig. 10 and kthe rod 'I0 is extended therefrom. I

When pressure is applied to the foot pedal I2,

.m the lever I3 tends tofulcrum about its connection with the rocker lever I5 in a direction which will not at first move the rod 9 tothe left as viewed in Fig. 1, but instead the lever Il willbe moved in`a direction to straighten the lever 45 I3 and rocker lever I5 and such movement will `rlrst operate the cross-shaft I6, lever arm I1 and brake rods II so that the brake bands will be moved into engagement with the brake drums 'and then continued movement of the rod Il by applying pressure to foot pedal I2 will cause the upper end iajof link I3 to be moved counterclockwise about its 'connection with rocker lever I5 and thereby pulls the valve head 31 against its exible valve seat portion 4B, closing communication between chamber A and chambers B and D pf the valve structure and booster unit respectively. Engagement of the valveh'ead 31 with the flexible platewhich, it should be not/ed. is applied` adiacentthe wall 21;`tends to lift the o0 :marginal flap valve portion 45 of said flexible plate and thereby provides communicationI .be-

t -tween the manifold line 5, the booster line 6, and

chamber D ofthe booster unit. The resistance offered by reason of sub-atmospheric pressure or i the creation of a partial vacuum within the channel 26 by the suctions of the engine connected in.V

the manifold 5, together with the connection p with brakepedal arm I2 through lever,I3 per-f mits the brake pedal arm I2 to exertsufflcient pull on the `brake rods -I I to take up all slack and bring the brake bands of the several wheels into contact with their vdrums before the'iiap valve portion 45 '-z'racks or opens; This prepar'the' mechanical parts ofthe braking arrangementi'or l 7s thepplicati'on of the vacuum power so that unclockwise above in connection with the connect- -ing rod I4y attached to the brake pedal which 10 causes the rod y9 to move to the right as viewed in 1 Figs. 1 and.2 or in adirection to close the communication between the manifold line and the booster line and to open the booster line to atmosphere. However, this contra-movement is 15 arrested; that is, the equilibrium is reached. when the vacuum in the chamber D of the booster unit reaches a value which is variable withV or dependentV upon theposition of vthe brake pedal. AThe further the brake pedal is depressed the 20 greater the vacuum created within thechamber D and the greater the force applied to the brake rods and brakes. Shouldflrthere be leaks in the booster line or valve structure, the communication between the manifold line 4 and booster 25 will be maintained, unlesszthe amount of leakage should exceed the capacity'fof the manifold line, as the booster unit cannotfact to shut off such communication with the manifold line until the` vacuum chamber .D is sufilcient to cause the 30 requiredmovement o f rod I0. .y

Release of the brake pedal permits spring 42 to Aurge the valve head 31 to'its'fjopen position and the exible valve portion 45 is immediatelyvdrawn onto the edge wall 21 by the vacuum created in 35 channel 26 thereby immediately preventing further application of such vacuum around the edge of wall 21 and through chamber B and booster line 8 to the booster andthen the varve head 31 is moved off from thel valve seat portion 48 and 40 thereby permitting the booster to be opened to the atmosphere through the openings l0, M and channel 4I so that thevacuumiri thevbooster is thereby exhausted.

lShould the vacuum power apparatus fail, the 45 brakes'are manually operative mechanically as thebrake pedal is mechanically connected with the brake rods.- The rod 3 merely moves to its left as viewed in Fig.` l until the tension plate II vengages'the inner end of the sleeve 3l which pror0 `jects into chamber A whereupon lever I3 acts as a variable fulcrulnY for said lever I5 which when so fulcrumed, pulls positively upon rocker lever I 5. From the foregoing it will be seen that during the rst operation of applying the brakes that 55 l the link or lever I3 will be moved slightly Vupward at its free end to which the rod' 9 `is cons nected, but that such upward movement will not aiect the valve structurel because such rod 9 is pivoted thereto as at t'. 'Ihis enables the valve` 60 structurel to be rigidly attached to the freine -member 2 as shown in Fig. 1. However, in some installations the upper end Ita of 'link I3 may be connected directly to the valve stem or rod 9" and in such installationseither a pivotal 'connec- 65 tion is interposed between the valve structure I and frame member 2 or the bar 3 is connected to such member 2 by a ball and socket Joint meansV so as to compensate for the slight `tilting movement that maybe the link I3. 1 l

. Attention is now directed particularly to Figs.

4-10- lTm'M'Itmsernent here 'illustrated isjpar-Tm ticularly-suitedfor trailer installation, `but is not to such m-tms embodiment of the occasioned lby operation of 70v f The tankY 65 is .connected through a storage"y line 66 with a relay valve means 61 which is con- A nected by a control line 68 with the hand control valve 64. A main booster line 69 leads from the relay' valve means 61 and is provided with branches 10 each of which leads to a booster unit 1. AIn this arrangement each booster unit is supported by a bracket 54 extending from the housing 12 or other suitable support adjacent the brake 13. The rod 0 of each booster unit is connected directly to a lever 1| protruding from the corresponding brake 13.

The hand control valve 64 and relay valve means 61 are in most respects similar to the hereinbefore described control valve structure and the identical elements thereof are designated similarly to said control valve structure.

In the hand control valve 64, see Figs. 5 and 6, a cover 8| is substituted for the cover 22, a stem 82 replaces the stem 9, and valve 83 replaces valve head` 31. The cover 8| isy provided with a centrally disposed bore through which the stem 82 is slidably received. Said. stem 82 extends through the flexible portion of plate 33 and is provided with a pair of washers 84 having convex confronting surfaces between which is mounted the valve 83-which is in the form of a nat. yieldable metallic plate, but having some degree of stiffness. Said valve 83 Ycoacts with the exible plate 33 in a manner similar to the rst described structure but with certain differences to be hereinafter brought out.

The outer portion of the stem 82 is provided with a socket |50 which is intersected by a laterallydirected diametrically disposed slot 5| through which extends a cross pin or cam .riding pin 85. The extremity ofthe stem 82 is enlarged and externally threaded to receive a. regulator knob 86 having an internally threaded socket |52 and a centered stop pin 81 projecting from said knob 86 `through socket |52 and into the stem 82 and against the cross pin 85. The cover 8| is provided with a bearing portion 88 s1otted`to receive thecam riding pin and about which is journalled cam ring 89 havingA a pair o! helical cam surfaces 90 at its axially outer side which extend almost 180 degrees terminating instopV lugs 9| at their raised ends-and-recesses 92 atA their lower ends adjacent lugs 9| as shown best in Fig, 6. The protruding extremities of the .cam riding pin 85 is urged against the cam surfaces 90 by the spring 42 so that engagement of the cam riding pin 85 with the cam, limits the inward or normal position of the valve 83 and flexible marginal valve 45, of the flexible partition 33. Adjustment of the regulating knob 86 raises and lowers the stem 82 for any given position relative tothe cam ring 89; thus providing a simple and positive means to regulate the limits of action of the hand control valve on raising or lowering of the valve 83 and flexible plate 33.

The cam ring 89 is operated by a handle93 whichcomprises a hand grip portion |53 and an inverted cup-shaped hub portion 94' which encloses the -cam ring but exposes the stem 82 will be away from plate 33 and in .by raising the valve 8 3 through opening |54; and regulating knob 86 is above the hub portion. Said hub portionis attached in fixed relation to the cam ring 89 by set screws 95 or the like.

The channel 26 of the hand controlled-valve 64 is connected with the branch 62 of the manifold line 6| while chamber B communicates with the control line 68 leading to the relay means 61. A

suitable vacuum gauge |56 is also connected with chamber B through the connection |55.

The relay valve means 6 1 differs over the rst described control valve structure in that it is operated by suction rather than by rod 9. For this change, aV cover |0| is substituted for the cover 22, a valve stem |02 is substituted for valve stem 9", and the valve head 31 is preferably bowed or tapered from valve stem |02 toward its periphery slightly away from the flexible plate 33 and is provided aroundV its outer periphery with a beaded rim |51 which is curved or rounded from the apex of the rim 51 to the outer periphery ofthe valve head 3]' the purpose of which will be more fully hereinafterexplained. Further, a flexible diaphragm |03 is interposed between the The valvestem |02 extends throughthe diaphragm |03 suflciently to receivea nut anda tension washer |04. A spring |05 is interposed between the tension washer and cover 0|, and` a cushion sleeve |06 is positioned between the diaphragm |03 and the tension plate 4|.

The interior of ycover |0| which forms an additional chamber E communicates with the control line 68 while channel 26 communicates with the storage line 66, and hence with the manifold line; the chamber B communicates with the main booster lines.

In brief both the hand control valve and relay valve means, like the controly valve structurehave chambers A and B as well as channel 26, but in the relay valve means, chamber A is divided and an additional chamber E is formed in the cover |0|. 'Their differences lie principally in their means of actuation; that is, the handcontrol Valve regulates the flow of air between chambers A and B and channel 26 b'y a hand lever and cam action in place of the link and lever and rod action of the control valve With the above in mind, operation of the apparatus disclosed in Fig. 4 is as follows:

Assuming that there is a sub-atmospheric pres- ,sure inthe tank 65 and the brakes are released, the3 relay valve means will be in the position shown in Fig. 8, but the hand controlled valve will be arranged with the flexible valve portion,

45 seated over the channel 26 and the valve 83 open position, contraryto the partially open the channel 26, as shown in Fig. 5. Upon turning the handle |53 to raise the valve 83, the

position of condition shown in Fig. 5 will obtain; that is,

30 nected directly to such chamber instead of vto 'Binhandcontrolvalveilandtochamberl'lin mined degree the flexible valve portion ll mayv the relay means..

Now, attention is called to the fact that the valve is yieldable, so that it tends to yield to atmospheric pressure in chamber A upon the flexible valve portion l5 whereby said valve portion may seat on wall 21 while the' valve remains closed. As the valve is raised in response.` to movement of the handle $3 and cam ring lrgreater effort is required to clou theilexible valve 46 and greater will be the vacuum in the chamber'E. This variation inthe degree of vacuum in chamber E as controlled by the handle .$3 causes a corresponding-'variation in the degree of vacuum in the several booster units in order to seat the exible valve in opposition to vacuum force or pull applied to diaphragm |03. That is, thereoccurs a balancing o! presvsures in chambers E andBof the relay valve means and a degreev of vacuumisjmaintained in the` booster units corresponding to lthe `degree voi? :vacuumin chamber E as controlled bythe position-of handle 83. w

The yieldable valve Il also provides means whereby the vacuum or sub-atmospheric pressure applied to the E in the remote control valve when the controlA line Il is conf nected to such chamber E,or the vacuum builtup in chamber D when the control line 8l is con the chamber E as is contemplatedfby this invention, will bemaintained at a uniform degree or pressure because when the vacuum built-up -in chamber B in the 'hand control valve M by the suction in the manifold 5 reaches a predeterbe drawn against its seat 21 thereby preventing the building up of greater sub-atmospheric pressure in the chambers lli! or D. as the case may be,v and the yieldable valve I3 will permit such valve portion 45- to close the channel 28 and still closetheeexhaustports III and Il, thereby maintaining the pressurebullt-up in the chambers D and E at a uniform degree and in the event the pressure in chambers D and E for any reason falls below that `pressure controlled by the' hand valve, -the valve portion 45 will be opened automatically due to the'diil'erences in pressures and again connect kthe suctionv of the manifold or-tank 65 to the chambers D or E` through the chamber B. In practice the storage tank BI, relay valve means 81 and booster units and connecting lines are mounted on the trailer, while the hand con-` trol valve is mounted on a suitable support. such as the dash board Il l. If desired, the relay -valve may be omitted and the main booster line B9. connected directly to thehand control valve in place of the line n.

By having the valve head 31 tapered valve .stem |02 towards the periphery of the valve headl' and providing such periphery with a beaded rim |51 the valve when moved to. open position will conform to the convexity ofthe valve member 33 and maintain'the exhaust openings in closed position and the curved or rounded edge |58 of the valve head 31' recedes from the iiexible platen and such construction has been Y found to effectively prevent uttering of valve 33 when in the open position thereby eliminating W,. thelikelihood o iobjectionable noises common in valves heretofore. Theouter :periphery ofv the valve head I1' just clears. an vinward profrom 'the chamber B and such periphery just passes such projection |58 when the exhaust openings 4|),

are closed and such construction permits kiml mediate and freer iiow past the valve head 31.'.

The tension washer |04 may be varied both as to thickness `and diameter to further control the operation of the valve by creating more weight to be raisedabythe vacuum or to increase 1 and 4decrease the area of the diaphragm N3 increases the thickness of boss `39 should be iiicreased so as to provide yproper time intervals in the action ot the various parts. f y

It will be apparent from the foregoing that as the valve stems 3l, liz-and |02 are moved upwardly or outwardly ci the housing that the exhaust ports are ilrst closed and further opening movement in the same direction of such yvalve stems opens the intake to the vacuum; and as said valve -stems are moved inwardly of the housing the inlet is rst closed and further. movement of the valve stems in such-latter direction will then open the exhaust ports and permit the vacuum to be exhausted. i

1.In ,a vacuum powercontrol apparatus for vehicles, a valve housing; a oating partition positioned within said housing to dene there-v valve seat portion coactiveiwlth said valve head to control iluid transfer from said central port to said atmosphere exposed chamber, and a freely .exibie peripheriai valve portion controlling. communication between said annular port andsaid central port; said atmosphere exposed chamber being cylindrical in form and having radially` directed atmosphere ports therein; a

cylindrical member within said chamber and correspondingly ported; and a screen' on said spacer member .covering -the ports therein. 1

2. In a vacuum power control apparatus for vehicles. .a valve housingfadapted to be attached in a fixed position to a vehicle frame; `a iloating partition'positioned within said housing to del iine therewith a central port and anannular port on one side ofthe partition and anatmosp'here exposed chamber on the other f side thereof;` ai valve head insald central port; a stem therefor extendingv through said partition; lsaid floating partition vbeing exibie and comprising a ported central portion covered by said valve head, a flexible valve seat portion coactive with said valvehead to control fluid transfer .fromsaid central port to said atmosphere exposedchamber,

and a freely iiexible. peripherial valve portion controllingcommunication between said annular vport and said central port; means operable through said stem for seating' said valve head against said valve seatportion, said means being further operable through said valve ..head and seat'to open said peripherial valve portion; said valve head being semi-flexible and responsive to K pressure differences between the sides of said" iection i that from the wall 21 into-epartitionidopposition to said means;

3.'In a vacuum power control apparatus for vehicles, a valve housing adapted to be attached in a fixed position to a vehicle frame including a first port in communication with a region of sub-atmospheric pressure, a second port in communication with a sub-atmospheric responsive device, and a chamber in communication with atmospheric pressure, a floatingly mounted ilexible partition separating saidy ports from said chamber, including, a valve portion controlling fluid transfer between said ports, and a valve seat portion aiording communication between said second port and said chamber; and a semiflexible valve head coactiva with said valve seat portion to control fluid transfer between said second port and said'chamber, said valve head being operatively connected with said valve portion throughsaid valve seat portion; means for operating said valve head to open said valve portion, said head being responsive to pressure diiferences between said ports and said chamber f to permit closing of said valve portion in opposition to said means. 7

4. In a vacuum power control apparatus for vehicles, avalve housing; a partition positioned within said housing to define therewith acentral portion and an annular port on one side of the partition and an atmosphere exposed chamber on the other side thereof; a. valve head in saidy central port; a stem therefor extending `through said partition; said flexible partition being flexible and comprising a ported" central portion covered by said valve head, a flexible seat portion coactive with said valve head to control fluid transfer from said central port to said atmosphere exposed chamber, and. a freely flexible p'eripherial valve portion controlling communication between said annular port and said central port; an expansible chamber including a flexible diaphragm connected with said stem; and means for varying the pressurein said expansible chamber to fluctuate said diaphragm and valve stem to actuate said valve stem.

5. In a vacuum power control apparatus for vehicles, a valve housing; a floating partition and a diaphragm positioned within the housing there being defined bythe diaphragm and housing an expansible chamber. by the partition and housing a central port and an annular port, and by and between said partition, diaphragm and housing an atmosphere exposed chamber, the centralportion of said partition 'forming a iiexiblevalve lseat means,for said central port, and' a peripherial portion of said partition forming a flap valve means for said annular port, a valve head arranged to coact with said valve seat means to control said central port and to actuate said flap Avalve means' through. said valve seat means,

means connecting said'valve head with said diaphragm; and means `for varying the pressure in said expansible chamber to fluctuate said' diaphragm and actuate said yalve.

6. In a vacuum power control apparatus for vehicles, a valve housing; a' floating partition positioned within said housing to dene therewith a central port and a'n annular port on one side of the partition and an atmosphere exposed chamber on the other side thereof; a valve head in said central port; a stem therefor extending through said partition; said oating partition being flexible and comprising a ported central portion covered by said valve head, a ilexible valve s'eat portion coactive with said valve head to con- .itmosphere exposed chamber; and a freely ilexible peripheral valve portioh controllinglcommunication between said annular port and said central port; and a fluid pressure responsive means in said housing connected with said stem to actuate said valve head whereby the said iiuid pressure in said central port is maintainednormally balanced against the said fluid pressure responsive means.

7. In a vacuum power control apparatus for vehicles, a valve housing;` a oating partition positioned within said housing to define therewith a central port and jan annular port on one side yof the partition` and an atmosphere exposed chamber on the other side thereof; a valve head in said central port; a stem therefor extending through said partition; said floating partition being flexible and comprising a ported central portion covered by said valve head, said portion coactive with said valve head to control iluid transfer from said central port to said atmosphere ,exposed chamber; and a freely iiexible peripherial yalve portion controlling communication between said annular port and said central port; a cam rider carried by said stem in said housing; a cam means journalled concentrically with respect to said stem and having a helical cam face engageable with said cam rider tofshift said stem axially and eiect movement of said valve head.

'8. In a vacuum power control apparatus, a housing,a chamber in said housing normally open to the atmosphere;.an outlet chamber in said housing adapted to be connected to a remote point; an inlet chamber surrounding said outlet chamber and having a seat portion interposed therebetween, a floating iiexible valve member interposed between said outlet chamber and said atmosphere chamber and adapted to normally close said inlet chamber; there being openings through said floating valve member normally connecting said outlet chamber to-said atmosphere' chamber; a flexible valve head normally spaced from said oating valve member and below said seat portion; means to normally urge said valve I from said seat portion to permit communication .between said inlet chamber and said outlet chamber and to prevent communication between said inlet and outlet chambersl and` said atmosphere chamber. 1

9. In a vacuum power control apparatus, a housing, a chamber in said housing normally open to the atmosphere; an outlet chamber in said housing adapted to be connected to a remote point; an inlet chamber surrounding said outlet chamberandhaving a seat portion interposed therebetween; a exible valvemember interposed .between said outlet chamber and said atmosphere chamber and adapted to normally engage said seat portion to prevent communication between said inlet chamber and'A said outlet chamber; a diaphragm connected to said housing and sepa- A rating said atmosphere chamberfrom said houssaid diaphragm; there being openings through trol fluid transfer from said central port to said said flexible valve member normally connecting said atmosphere chamber :and said outlet chamto flex said diaphragm and to move said valve head to close said openings in said iiexible valve and to raise said ilexible valve oil' ironi said seat so as to permit communication between said inlet chamber and said outlet chamber.

10. In a vacuum power control apparatus for vehicle brakes; 'a booster unit connected to operate said brakes and having a chamber responsive to sub-atmospheric pressure variation; a region of sub-atmospheric pressure; means to control the application ot said pressure; a control valve connected to said region of sub-atmospheric pressure and including. a housing having an outlet chamber connected to the chamber in said booster unit, an inlet chamber of lesser area than said outlet chamber connected tosaid region o! subatmospheric pressure, a chamber connected to the atmosphere, a oating exible valve member interposed between said outlet chamber and said atmosphere chamber and adapted to normally close communication between said inlet chamber and said outlet chamber, a diaphragm connected to said housing and separating said atmosphere chamber from said housing and providing an additional chamber therein, said additional'chamber being connected to said region of sub-atmospheric pressure subject to control of said means i controlling the application of said pressure; and

means whereby a sub-atmospheric pressure applied ,in said additional chamber will be auto'- matically maintained in said outlet chamber and the chamber in said booster unit in substantially the same amount as that applied in said additional chamber.

11. In a vacuum power controlled apparatus `for vehicles,A a valve housing, a exible partition and a diaphragm positioned within the housing there being defined by the diaphragm and housing an expansible chamber, by the partition and housing a central port and an annular port, and by and between said partition, diaphragm and housing an atmosphere exposed -chamber, the central portion of said partitionforming a flexible valve seatmeans for said central port, and the peripheral portion of said partition formingv a ap valve means for said annular port, a valve head arranged to coact with said 'valve seat, means to control said central portand to actuate said nap valve means through said valve seat means, means connecting said valve head with said diaphragm and means for varying the lpx'esl ALBERT E. ROY. 

